After the long term evolution (LTE) system has gone through several releases of R8/9/10, R11 technology will be researched in the future. Currently, some R8 products are gradually commercially available, and R9 and R10 products need to be further planned.
After having gone through R8 and R9 stages, R10 adds many new properties on the basis of the former, for example, pilot frequency properties such as DMRS (Demodulation Reference Signal), CSI-RS (Channel State Information Reference Signal), transmission and feedback properties such as 8 antenna support and so on, especially eICIC (enhanced Inter-Cell Interference Cancellation) technology takes into account the interference avoidance technology among cells on the basis of taking into account R8/9 ICIC. For the technology which solves the interference problem among cells, at the initial stage of R10, cell interference avoidance in a homogeneous network is mainly taken into account, wherein what are mainly taken into account are eICIC technology and CoMP (Coordinated Multi-point) technology. Just as its name implies, CoMP is that a plurality of CSI-RS configuration resources and/or interference measurement resources coordinate to send data to one or more UE in the same time frequency resources or different time frequency resources. CoMP technology can reduce inter-cell interference, improve cell edge throughput and enlarge cell coverage. However, since the situation where the homogenous network introduces more scenarios is taken into account at the later of discussion, in view of the complexity of CoMP technology and the temporal limitation of R10 discussion, finally it is decided not to introduce additional CoMP standardization contents at R10 stage, however, design can be made by taking into account the demand of the CoMP part when designing CSI-RS, and therefore, CoMP technology is not discussed further after 60 bis conference.
At the initial R11 discussion SI (study item) stage, a unified evaluation architecture is determined by planning scenarios and various transmission technologies of CoMP, and it is proved that CoMP technology can obtain significant performance gain after two stages of CoMP evaluation. Recently completed CoMP SI conclusions are that it needs to further research JT (Joint Transmission), DPS (Dynamic Point Selection) with/without muting, CS (Coordinated Scheduling) with/without muting, CB (Coordinated Beamforming) in CoMP technology.
Before researching various technologies of CoMP, it needs to first take into account CoMP technology has what differences for R8/9/10 technologies, which includes how the control signalling of CoMP supports the notification of a CoMP measurement set, how to support the demands of different transmission technologies of CoMP and how a UE measures and reports the CSI (Channel State Information) and so on of a plurality of CSI-RS configuration resources and/or interference measurement resources. How a UE measures and reports the CSIs of a plurality of CSI-RS configuration resources and/or interference measurement resources is one of the primary problems to be solved. In the current discussion, the feedback of CoMP can be mainly divided into periodical feedback and non-periodical feedback, and aggregated channel information feedback and non-aggregated channel information feedback. The so-called aggregated channel information feedback refers to that the channel information about a plurality of CSI-RS configuration resources and/or interference measurement resources are aggregated into one piece of channel information of CSI-RS configuration resource and/or interference measurement resource for global feedback. For example, a measurement set contains two CSI-RS configuration resources and/or interference measurement resources, wherein the channel information about CSI-RS configuration resource and/or interference measurement resource 1 is H1, the channel information about CSI-RS configuration resource and/or interference measurement resource 2 is H2, and at this moment, the UE first aggregates the channel information about two CSI-RS configuration resources and/or interference measurement resources into a large piece of channel information, expressed with H=[H1; H2], and then measurement relevant calculation and feedback are performed. Non-aggregated channel information feedback can also be divided into independent single cell feedback and independent single cell feedback plus inter-cell correction information. The so-called independent single cell feedback refers to independently performing measurement relevant calculation and feedback according to the channel information about each CSI-RS configuration resource and/or interference measurement resource. The so-called independent single cell feedback plus inter-cell correction information refers to independently performing measurement relevant calculation according to the channel information about each CSI-RS configuration resource and/or interference measurement resource, and calculating the phase and/or amplitude information about each CSI-RS configuration resource and/or interference measurement resource and performing feedback. For feedback whereby aggregated channel information includes an aggregated CQI, aggregated CQI refers to that the CQI fed back by the UE side corresponds to the aggregated CQI for measuring one or more pieces of CSI-RS configuration information and/or interference measurement resource information, and the UE finds the time frequency location of a corresponding CSI-RS using a plurality of pieces of CSI-RS configuration information and/or interference measurement resource information, so as to perform measurement and obtain precoding weight information and obtain interference information using other pilot frequencies and then perform calculation, and at this moment, the UE assumes that there are CSI-RS configuration resources and/or interference measurement resources corresponding to one or more pieces of CSI-RS configuration information and/or interference measurement resource information sending data thereto, thus obtaining a CQI value corresponding to the joint transmission of the plurality of CSI-RS configuration resources and/or interference measurement resources. Since one aggregated CQI may correspond to an aggregation for measuring one or more pieces of CSI-RS configuration information and/or interference measurement resource information, for example, a measurement set may contain 3 pieces of CSI-RS configuration information and/or interference measurement resource information, and at this moment, there are 3 possibilities for aggregating one piece of CSI-RS configuration information and/or interference measurement resource information, there are 3 possibilities for aggregating two pieces of CSI-RS configuration information and/or interference measurement resource information, and there is one possibility for aggregating one piece of CSI-RS configuration information and/or interference measurement resource information, totally 7 possibilities, and therefore, there are many possibilities for an aggregated CQI, each possibility can be referred to as an aggregation possibility, that is, an aggregated CSI-RS configuration resource and/or interference measurement resource is aggregated of at least one configuration CSI-RS configuration resource and/or interference measurement resource, and the current constituent manner is referred to as aggregation possibility.
For traditional R8/R9/R10, a user merely needs to feed back the CSI of the serving cell, and therefore, over the same carriers, it merely needs to take into account single cell capacity for periodical feedback and non-periodical feedback, especially for a PUCCH, it merely needs to optimize the feedback of a single cell. Currently, taking into account coding and HARQ (Hybrid Adaptive Request Repeat) bit number and so on, for one UE, at most 11 bit CSI feedback is supported in one PUCCH (Physical Uplink Control Channel) uplink subframe. The constituent of 11 bits at most may take into account 4-bit PMI (Precoding Matrix Indicator) and two code word 7-bit CQI (Channel Quality Indicator) (taking into account the differential feedback of the CQIs among different code words). Since CoMP needs to take into account the CSI for a plurality of cells, it needs to have N*11-bit PUCCH capacity capability, however, the current PUCCH capacity cannot meet this requirement, a rational feedback solution is needed to solve the problem of insufficient PUCCH capacity. It is easily conceivable of compressing the feedback signalling, however, CoMP has relatively high requirements on the accuracy of CSI, especially, JT even JT-MU proposes relatively high requirements on the accuracy of CSI, and therefore, the performance loss caused by compression may lead to the decreasing of CoMP performance gain. Another consideration is to improve the capacity of the PUCCH, and this requires to redesign the feedback format of the PUCCH, which will inevitably bring significant standardization efforts. If it is taken into account the feedback requirements for CSI among different modes of CoMP and ensure adaptive switching among different modes, this feedback design may be more complicated. Thus, in discussion, it is taken into account information among CSI-RS configuration resources and/or interference measurement resources which can ensure the flexible switching of coordinated sending modes and/or introduce the concept of aggregated CQI. In a recent conference, it is discussed that the aggregated CQI can obtain and introduce performance similar to information among CSI-RS configuration resources and/or interference measurement resources+aggregated CQI, at this moment, no additional feedback of information among CSI-RS configuration resources and/or interference measurement resources is introduced, and currently, the conference still discusses whether to take into account the feedback of information among additional CSI-RS configuration resources and/or interference measurement resources. However, the two solutions mentioned above take into account the concept of aggregated CQI, and for the concept of aggregated CQI, it needs to feed back a CQI value generated by the aggregation of a plurality of CSI-RS configuration resources and/or interference measurement resources, the number of aggregated CSI-RS configuration resources and/or interference measurement resources can be a combination of any number of CSI-RS configuration resources and/or interference measurement resources in all the CSI-RS configuration resources and/or interference measurement resources in the measurement set, for example, the measurement set includes 6 CSI-RS configuration resources and/or interference measurement resources, at this moment, possible combinations include 63 situations, and if it is taken into account to limit the maximum number of CSI-RS configuration resources and/or interference measurement resources, the combinations include 41 possibilities. If the UE feeds back a plurality of CQIs in one feedback or feeds back a plurality of aggregated CQIs of various situations in a plurality of feedbacks, how the base station side learns the aggregated CQI fed back by the UE correspond to the combination of which CSI-RS configuration resources and/or interference measurement resources, this point needs to be specified uniformly at the base station side and the UE side, otherwise, the base station side cannot learn the received aggregated CQI correspond to the combination of which CSI-RS configuration resources and/or interference measurement resources.
Aiming at the problem mentioned above, no effective solution has been presented.